Liquid explosives



Patented Feb. 2, 1954 UNITED LIQUID EXPLOSIVES No Drawing. Application September 13, 1951, Serial No. 246,525

6 Claims.

The present invention relates to liquid explosives and is particularly concerned with providing a liquid explosive which among other uses can be employed in a flexible conduit for the demolition of landing obstacles or clearing mine fields during warfare.

The principal object of the present invention is to provide a low-freezing liquid explosive of high explosive power and moderate viscosity which is relatively insensitive to impact and will remain in good condition over long periods of storage.

It has been discovered that a liquid explosive meeting the aforementioned objects can be produced by phlegmatizing nitroglycerine with dimethylphthalate and including a stabilizer therefor. The resulting product is referred to throughout this specification as Methylite. The range of proportions of the various ingredients which have been found most suitable for the present purpose consists of 70% to 80% nitroglycerine with from about 19% to 30% dimethylphthalate and a stabilizer in amounts of 0.9% to 1% of the total nitroglycerine mixtureemployed. The above percentages represent proportions of the volume of the total liquid explosive.

A commercial grade nitroglycerine containing a freezing point depressant such as 25%:2% ethylene glycol dinitrate or 30% :L2% diglycerine tetranitrate is suitable for forming the Methylite.

Of these additives the ethylene glycol dinitrate i preferred as it is less viscous at low temperatures than the diglycerine tetranitrate.

As examples of stabilizers, ethyl centralite or diphenylamine have been found to be especially suitable for use in the present mixture. Either stabilizer should be present in amounts of 0.9% to 1% of the total nitroglycerine present including the aforementioned additives thereto.

In preparing the Methylite, the stabilizer is dissolved in the dimethylphthalate by stirring at 125 F. in an agitated vessel until the solution is complete. The resulting solution may then either be placed in containers and stored before use or added directly to the nitroglycerine.

Specific examples of acceptable mixtures forming Methylite are as follows:

The resulting products are low freezing liquids, with freezing temperatures of -4 F. (20 C.)

2 for mixture No.2 and -22 F. (-30 C.) for mixture No. 1. They have a moderate viscosity and high explosive power with a detonation velocity of 7000-7300 M./Sec. Solution No. 1 is designed to propagate an explosion in diameters as low as 1" when unconfined and solution No. 2 in columns of 3" or larger. The Methylite so produced can be stored over a period of many years and notably longer than nitroglycerine, without decomposition.

Methylite produced according to the present disclosure is insensitive to frictional impact such as being struck a glancing blow and also generally insensitive to direct impact. For instance Methylite contained in a Fiberglas hose and backed by air or even wood is not exploded when hit with cal. .50 ball ammunition. Similarly containers of Methylite dropped from considerable heights onto hard surfaces will not explode as long as the containers do not collapse and pinch the explosive between two parts thereof. Such characteristics of the Methylite renders the same safe for normal handling and transportation even under combat conditions.

A flexible conduit containing Methylite can be exploded by employing a two pound or more external booster of cast Pentolite, Tetrytol or the like for initiation of the Methylite in the conduit.

It is to be understood that other proportions of the ingredients can be used to form a liquid explosive besides those described herein but the proportions given are preferred mixtures having all Of the characteristics desired.

We claim:

1. A liquid explosive composition adapted to operation in a flexible conduit comprising to percent by volume of nitroglycerine, and from 19 to 30 percent by volume of dimethylphthalate.

2. A liquid explosive composition adapted to operation in a flexible conduit comprising 70 to 80 percent by volume of nitroglycerine, from 19 to 30 percent by volume of dimethylphthalate and from 0.7 to 1 percent of a stabilizer.

3. A liquid explosive composition adapted to operation in a flexible conduit comprising from 70 to 80 percent by volume of nitroglycerine, from 19 to 30 percent by volume of dimethylphthalate, and from 0.7 to 1 percent by volume of a stabilizer selected from the group consisting of ethyl centralite and diphenylamine.

4. A liquid explosive composition adapted to operation in a flexible conduit comprising 70 to 80 percent by volume of nitroglycerine, 19. to 30 percent by volume of dimethylphthalate, 0.7 to 1 percent of a stabilizer selected from the group 3 4 consisting of ethyl centralite and diphenylamine, References Cited in the file of this patent and 25-12% by volume of a. freezing point de- UNITED STATES PATENTS pressant selected from the group consistmg of ethylene glycol dinitrate and diglycerine tetra- Number Name Date nitrate 5 1,205,516 Cos by Nov. 21, 1916 5. A composition according to claim 3 wherein 1,836,563 wlghtsman 15, 1931 the stabilizer is ethyl centralite. 1,999,828 wlggam 30, 1935 6. A composition according to claim 3 wherein 2,003,839 Wagner July 1935 the stabilizer is diphenylamine. 0 FOREIGN PATENTS HOWARD J" FISHER Number Country Date DUNCAN P. MACDOUGALLV GEORGE B. KISTIAKOWSKY. 621,685 Great Brltam Apr. 14, 1949 

1. A LIQUID EXPLOSIVE COMPOSITION ADAPTED TO OPERATION IN A FLEXIBLE CONDUIT COMPRISING 70 TO 80 PERCENT BY VOLUME OF NITROGLYCERINE, AND FROM 19 TO 30 PERCENT BY VOLUME OF DIMETHYLPHTHALATE.
 2. A LIQUID EXPLOSIVE COMPOSITION ADAPTED TO OPERATION IN A FLEXIBLE CONDUIT COMPRISING 70 TO 80 PERCENT BY VOLUME OF NITROGLYCERINE, FROM 19 TO 30 PERCENT BY VOLUME OF DIMETHYLPHTHALATE AND FROM 0.7 TO 1 PERCENT OF A STABILIZER. 